The present invention relates to storage area networks and network attached storage. In particular, the present invention relates to a storage server that uses blocks of storage address space to virtualize different types of storage.
Storage virtualization describes the process of representing, to a user, a number of discrete physical storage devices as a single storage pool having a single set of characteristics. For example, in a storage area network connecting host computers with storage devices, the user perceives a single block of disk space with a defined reliability (e.g., 100 GB at RAID1); however, the user's host computer is configured to access the storage devices such that 100 GB at RAID1 is provided, regardless of whether the data is stored on a single RAID1 disk array or is split across multiple, separate disks.
In the above situation, each host computer must be aware of the storage devices connected to the storage area network because each host computer manages the storage virtualization that is presented to its users. When the storage devices connected to the storage area network are modified (such as a new device being added or an existing device being removed), each host computer must be reconfigured to accommodate the modification. Such reconfiguration involves work by network administrators and ensures that changes in the network are not seamless.
The present invention is directed toward improvements in this and other areas.